Vehicle wheel comprising a tyre and an assembly consisting of a valve a device for measuring the tyre pressure and a spring for holding said device in the tyre

ABSTRACT

An arrangement comprising a device for measuring the tyre pressure in a pneumatic tyre, which device is enclosed in a casing ( 1 ) which is located inside the pneumatic tyre when the pneumatic tyre has been mounted on a wheel, and further comprising a spring ( 2 ) acting resiliently upon the casing ( 1 ), and a holder ( 3, 25 ) for the spring ( 2 ) to be fixed on the wheel.  
     According to the invention the spring ( 2 ) and the casing ( 1 ) are so designed and adapted one to the other that the casing ( 1 ) finds support on the holder ( 3, 25 ) and is clamped for this purpose between the spring ( 2 ) and the holder ( 3, 25 ).

[0001] The present invention relates to an arrangement having thefeatures set out in the preamble of claim 1, and to a wheel having thefeatures set out in the preamble of claim 15.

[0002] A wheel for motor vehicles equipped with pneumatic tyres, wherethe casing of a tyre pressure measuring device is firmly connected withthe base of the valve by screwing, has been known from EP 0 751 017 B1.The valve bore, through which air can be pumped into the tyre, isprovided with a threaded bore for this purpose, and the casing of thetyre pressure measuring device is provided with an oblong hole throughwhich a hollow screw can be screwed into the thread of the valve bore.The screw is firmly tightened so as to fix the casing on the valve base.For this purpose, the valve is made from metal and has a calotte-likeouter shape which allows it to be snugly seated in a recess ofcomplementary calotte-like shape in the casing of the tyre pressuremeasuring device. In order to permit the casing to find support on therim well, the casing is provided with two feet serving to support it onthe rim well. In order to ensure that the feet will actually reach therim well even with differently shaped rims, the oblong hole permits thecasing to be fixed on the valve base in different orientations relativeto the longitudinal axis of the valve bore. This design allows one andthe same casing of the tyre pressure measuring device to be firmlymounted in wheels with differently shaped rims. It is, however, adisadvantage that for mounting the casing of the tyre pressure measuringdevice one needs an especially adapted valve whose valve bore in thevalve base is configured as a threaded bore and is adapted to receive abored special screw by means of which the casing can be screwed down onthe valve base. Such a bored special screw is expensive. In addition,the casing of the tyre pressure measuring device must be provided with adeep indentation in order to permit the screw to be introduced throughthe oblong hole and to be screwed into the valve base using a screwdriver. The deep indentation in the casing restricts, however, the innerspace of the casing and divides it into two compartments, which limitsthe free arrangement of the electric and electronic components in thecasing.

[0003] An arrangement having the features of the preamble of claim 1,and a wheel having the features of the preamble of claim 20 has beenknown from DE 196 26 145 A1. In the case of this known wheel, instead ofscrewing the casing of the tyre pressure measuring device onto the valvebase, a spring is used whose free end acts upon the casing so as toclamp the casing between the free end of the spring and the vehicle rimin such a way that the casing will be supported, on the one hand, on thebase of the rim well and, on the other hand, on two supporting points onthe sidewall of the rim well. The spring therefore urges the casingagainst both the base of the rim well and the sidewall of the rim wellso that the casing is embraced on four sides, namely by the spring ontwo sides, by the rim well on one side and by the sidewall of the rimwell on one side. It is a disadvantage of that arrangement that just asin the case of the arrangement described by EP 0 751 017 B1, anexpensive bored special screw is required in this case for mounting thespring on the valve base. Further, it is a disadvantage that differentlyshaped springs are required for differently shaped rims in order to urgethe casing against, and to fix it on the rim.

[0004] Now, it is the object of the present invention to open up a wayof mounting a casing with a tyre pressure measuring device on differentrims for wheels with pneumatic tyres, at reduced cost and in a moreuniversal way.

[0005] This object is achieved by an arrangement having the features setout in claim 1 and by a wheel having the features set out in claim 20.Advantageous further developments of the invention are thesubject-matter of the sub-claims.

[0006] The arrangement according to the invention provides that thecasing containing the tyre pressure measuring device, the spring actingresiliently upon the casing, and the spring holder fixed on the wheelare so designed and adapted one to the other that the casing findssupport on the holder, and is clamped for this purpose between thespring and the holder. Contrary to the arrangement known from DE 196 26145 A1, the holder not only holds the spring but serves an additionalfunction in combination with the spring, namely the function of asupport for the casing containing the tyre pressure measuring device. Inthis respect, the casing, the holder and the spring coact in a veryspecial way in that the casing is clamped between the spring and theholder. This distinguishes the arrangement essentially from thesubject-matter of DE 196 145 A1: While in the latter case, the springacts exclusively to press the casing against the rim, i.e. against therim well and against the sidewall of the rim which delimits the rimwell, the spring according to the invention acts to urge the casingagainst the spring holder. This provides a universal way of mounting thecasing on any type of rim because the points of engagement between whichthe casing is clamped, being defined by the holder and the spring, canbe associated one to the other irrespectively of the particular rimused. In addition, a pre-assembled unit can be formed from the holder,the casing and the tyre pressure measuring device and the spring, whichcan then be handled as a unit and mounted as a unit on the rim.

[0007] The holder may be the base of a valve through which the pneumatictyre is to be inflated. This solution is preferred for well-base rims,which are common in passenger cars. In the case of well-base rims, thevalve is seated in a hole in the sidewall of the rim, that delimits thewell base, and has its longitudinal axis extending at an angle relativeto a vertical line. In the case of such an arrangement, the valve base,located inside the pneumatic tyre, is particularly well suited forsupporting the casing of the tyre pressure measuring device. When thespring is mounted on the valve base as well, which is the case in thearrangement according to the invention, so that the casing can beclamped between the valve base and the spring, then one can do withoutan expensive special screw of the kind needed in the mountingarrangement according to EP 0 751 017 B1. And if no bored screw isneeded, there is also no need to provide an indentation in the casing toallow such a screw to be fitted. Instead, the casing can be designedwithout giving consideration to any severe restrictions resulting fromthe mounting technique.

[0008] In the case of trucks, where the valve is usually seated radiallyin a hole in the flat base of a flat-base rim, the valve base, beinglocated inside the pneumatic tyre, is less suited for holding the springand supporting the casing of the tyre pressure measuring device. In thecase of a flat-base rim, one therefore preferably uses a separateholder, which is fastened on the rim using a tightening strap embracingthe rim well. Tightening straps are known in the field of installationengineering. With such tightening straps, any changes to the rim and anysoldering work on the rim, that may otherwise be necessary for mountingthe holder, are rendered superfluous. The strap may consist of a plasticmaterial or of metal. Preferably, metallic tightening straps are used.The holder for the spring may in that case consist of a sheet-metalpart, which can be produced at low cost by punching, bending andstamping operations. Such a holder preferably comprises a first part incontact with the rim well and a second part projecting from the rimwell, on which the casing finds support in the clamped condition. Theorientation and contour of the second part, which projects from the rimwell, are preferably selected to be identical or similar to theorientation and contour of the valve base for a well-base rim. It canthus be ensured that the tyre pressure measuring device can be mountedin flat-base rims with the same casing as in well-base rims.

[0009] In order to permit the holder to be fixed in a flat-base rim inan especially safe way, its first part, which is in contact with the rimwell, may preferably be formed as a double loop through which thetightening strap is passed.

[0010] It is an essential feature of the invention that the casing issupported on the housing and is clamped between the spring and theholder. This does not, however, exclude that the casing may beadditionally supported on the rim. In fact, this is even preferred inorder to give the casing a more stable position. The spring is,therefore, preferably designed and arranged so as to push or pull thecasing additionally against the rim well. When the spring pushes thecasing against the rim well, then it is arranged above the casing and ispre-shaped and mounted on the holder in such a way that the casing canbe positioned below the spring only when the spring is bent away fromthe rim well, whereby the spring is biased. In contrast, when the casingis pulled against the rim well, then the spring is arranged below thecasing and is biased into contact with the rim well. In both cases,however, there is no need for the casing to be supported on a sidewallof the rim delimiting the rim well, the casing being already supportedon the holder.

[0011] Being clamped between the spring and its holder, the casing is inany case held by the spring action. Preferably, it is held between theholder and the spring not only by the spring action, but is held alsopositively, i.e. by form-locking means, in order to be absolutely surethat the casing cannot move out of its holder. The casing is providedfor this purpose with a recess intended to receive a portion of theholder. A holder having a convex shaped end, especially in the form of acalotte, is particularly well suited. In this case, the casing should beprovided with a concave recess matching the convex end of the holder,for receiving the convex end of the spring. This allows not only apositive and a spring action engagement of the holder in the casing, butalso an automatic centering and an automatic alignment of the casing inthe position best suited for fixing it.

[0012] Conveniently, the spring is a leaf spring. The form of such aleaf spring can be adapted to the contour of the casing with specialease, can then easily embrace the casing, and is capable of generatingsufficient spring power.

[0013] The spring can be held on the holder in different ways. It may beconnected with the holder by screwing or by a self-substance connection.It can also be positively connected with the holder, in which case theholder can be provided with an annular groove which can be engaged by afork provided on the spring. In this case, the fork may even engage theholder loosely, provided it is urged into the annular groove of theholder by the spring tension prevailing in the spring after the springhas been mounted on the casing. There is, however, also the possibilityto screw a screw into that end of the holder on which the casing issupported, and to clamp one end of the spring, which is provided with ahole, between the head of the screw and the end of the holder. The screwrequired for this purpose needs not be a bored special screw—as requiredin the prior art—but may be a cheep standard screw.

[0014] Positive engagement is of advantage not only between the casingand the holder, but also between the casing and the spring. The springis, therefore, preferably provided with a stirrup, which receives thecasing in centrally arranged receiving means, especially in a shallowgroove, which is particularly well suited for receiving a leaf spring.While this simple arrangement is suited to prevent the casing fromgetting displaced, the depth of the groove may be so small that it hasno practical effect on the free inner volume of the casing. In order tokeep any tilting moments as small as possible, the casing should bemirror-symmetrical relative to its central receiving means, which ispreferably configured as a shallow groove.

[0015] Even better retention for the spring is achieved by the use of aspring comprising two mutually parallel stirrups with a commonconnecting element by means of which the spring can be mounted on theholder. This connecting element may consist of an eye or a fork, forexample. For mounting the two parallel stirrups, the casing is in thiscase provided with two parallel receiving means, for example two shallowgrooves, conveniently arranged in symmetry relative to the centre planeof the casing that contains a longitudinal axis of the holder, forexample the longitudinal axis of a valve. Any tilting moments that maybe produced by rotation of the wheel when the vehicle is moving, can beoptimally controlled in this way.

[0016] For supporting the casing on the rim well, the underside of thecasing is conveniently provided with two projecting feet located ondifferent sides of the centre plane of the casing. One thus achieves astable three-point support for the casing, with two supporting points onthe rim well and a third supporting point on the holder on which thecasing is located by the spring.

[0017] In cases where the base of a valve is used as a holder for thespring and as support for the casing, the casing preferably is traversedby an air flow channel with the valve opening into that channel. The airflow channel needs not, however, to have a large cross-section so thatit will not substantially reduce or restrict the inner space of thecasing.

[0018] Certain advantageous embodiments of the invention are illustrateddiagrammatically in the attached drawings in which identical parts, orparts corresponding one to the other, are identified by the samereference numerals. In the drawings:

[0019]FIG. 1 shows an isometric, exploded view of a first embodiment ofan arrangement comprising a casing for a tyre pressure measuring device,a spring and a valve;

[0020]FIG. 2 shows an isometric view of the arrangement of FIG. 1,viewed at a different angle;

[0021]FIG. 3 shows an isometric view of the arrangement of FIG. 1 afterassembly;

[0022]FIG. 4 shows an elevation of the arrangement of FIG. 3;

[0023]FIG. 5 shows a bottom view of the arrangement of FIG. 3;

[0024]FIG. 6 shows a different elevation of the arrangement of FIG. 3;

[0025]FIG. 7 shows a section along line A-A in FIG. 5;

[0026]FIG. 8 shows an isometric, exploded view of a second embodiment ofan arrangement comprising a casing for a tyre pressure measuring device,a spring and a valve;

[0027]FIG. 9 shows an isometric view of the arrangement of FIG. 8 in apartly assembled state;

[0028]FIG. 10 shows an isometric view of the arrangement of FIG. 8 inthe completely assembled state;

[0029]FIG. 11 shows a top view of the arrangement of FIG. 10;

[0030]FIG. 12 shows a front view of the arrangement of FIG. 10;

[0031]FIG. 13 shows an elevation of the arrangement of FIG. 10;

[0032]FIG. 14 shows an isometric, exploded view of a third embodiment ofan arrangement comprising a casing for a tyre pressure measuring device,a spring and a valve;

[0033]FIG. 15 shows an isometric view of the arrangement of FIG. 14, inthe completely assembled state, with additional parts for assembly andcompletion of the valve;

[0034]FIG. 16 shows another isometric view of the arrangement of FIG.15;

[0035]FIG. 17 shows a top view of the arrangement of FIG. 15;

[0036]FIG. 18 shows an elevation of the arrangement of FIG. 15;

[0037]FIG. 19 shows an elevation of a fourth embodiment of anarrangement comprising a casing for a tyre pressure measuring device, aspring and a holder for such device, where the holder is fixed on therim by a tightening strap; and

[0038]FIG. 20 shows a section along line A-A in FIG. 19.

[0039] The arrangement illustrated in FIGS. 1 to 7 comprises a casing 1,a spring 2 and a valve 3 serving as holder for the spring 2. The valve 3comprises a shaft 4, which is inserted from the inside into a hole of arim provided—in the case of a well-base rim—in that sidewall of the rimwhich delimits the well base. The valve 3 is inserted into the hole inthe rim until its collar 5 abuts against the rim, and is then screweddown on the rim from the outside using the mounting means illustrated inFIGS. 15 to 18. After the valve 3 has been mounted on the vehicle wheel,the collar 5 and a valve base 6, having a calotte-shaped surface, arelocated in the pneumatic tyre. Between the collar 5 and the calotte ofthe valve base 6, there is provided an annular groove 7, which isengaged by a fork 8 provided on one end of a spring 2, which latter isdesigned as a leaf spring. A centering nose 9, provided on the spring 2between the two prongs of the fork 8, ensures that the fork 8 occupies apredetermined position in the annular groove 7, by engaging a recess inthe bottom of the groove 7 not visible in the drawing.

[0040] The spring 2 is repeatedly bent off to assume a roughly C-shapedconfiguration. It is, consequently, capable of encompassing the casingfrom its top. For this purpose, the casing 1 is provided with a shallowgroove 10 on its upper surface and on the side facing away from thevalve 3. The shape of the groove 10 and the shape of the spring 2 arematched one to the other so that a stirrup 2 a of the spring 2,following the fork 8, can engage the groove 10 in a positive engagementand, simultaneously, in an engagement under spring action.

[0041] As seat for the spherical valve base 6, the casing 1 is providedon its side facing the valve 3 with a corresponding recess 11, shaped asa complementary calotte matching the valve base 6.

[0042] For mounting the arrangement, one first places the recess 11 ofthe casing 1 against the valve base 6, then inserts the spring 2 withits fork 8 into the annular groove 7 and pushes the opposite end 12 ofthe spring from the top into the shallow groove 10 until its forward end12 overcomes a snap-in edge 13 formed in the shallow groove 10 and getscaught behind the snap-in edge 13, thereby forming a moderate undercut.The dimensions of the spring 2 are matched to the dimensions of thecasing 1 so that the spring 2 necessarily has to bend resilientlyoutwards when being snapped onto the casing. This then has the resultthat the end 12 of the spring 2 urges the casing 1 against the valvebase 6 so that the casing 1 is supported on the latter. The casing 1,the valve 3 and the spring 2 now form an assembled unit.

[0043] For supporting the casing 1 on the rim well, the underside of thecasing is additionally provided with two feet 14 located near twolateral edges of the casing 1, at the greatest possible spacing one fromthe other. Together with the valve base 6 they constitute a stablethree-point support for the casing 1 in the pneumatic tyre of the wheel.In this respect, interaction between the calotte-shaped surfaces of thevalve base 6 and the recess 11 ensures automatic centering of the casing1 in its most stable position possible.

[0044] After pre-assembly of the arrangement, as illustrated in FIGS. 3to 7, it can be mounted on the rim of the wheel by inserting the valve3, with its shaft 4, through a hole in the rim provided for this purposeand by screwing it down from the outside. It is ensured in thisconnection by the corresponding shape of the spring 2 that the feet 14of the casing 1 are constantly pressed onto the rim well, which isguaranteed above all by the bent-off arrangement of the fork 8 relativeto the remaining spring 2.

[0045] The valve 3 includes a channel 16, which passes through the valvein the direction of its longitudinal axis 15 and ends at the position ofthe valve base 6. In order to permit the air, which flows through thechannel 16 when the tyre is being inflated, to flow through the valve aflow channel 17, starting out from the recess 11 and traversing thecasing 1, is provided in the casing 1 in alignment with the axis 15. Atthe opposite side, where the flow channel 17 comes to light again, it iscovered by the spring 2. In order to nevertheless permit the air to flowout, the spring is provided with a hole 18 at this point. Alternatively,the spring 2 could also be conveniently shaped at this point to providean air gap between the spring 2 and the groove 10.

[0046] The second embodiment, illustrated in FIGS. 8 to 13, differs fromthe embodiment illustrated in FIGS. 1 to 7 insofar as the spring 2 isprovided with two mutually parallel stirrups 2 a and 2 b connected viathe fork 8. Accordingly, the upper surface of the casing 1 is providedwith two mutually parallel grooves 10 a and 10 b intended to receive thetwo stirrups 2 a and 2 b of the spring. The underside of the casing isprovided in this case with a projecting edge 19, instead of the two feet14.

[0047] The third embodiment, illustrated in FIGS. 14 to 18, differs fromthe first embodiment illustrated in FIGS. 1 to 7 insofar as the spring 2embraces the casing 1 about its bottom rather than about its top.Accordingly, there is no shallow groove on the upper surface of thecasing 1. Nor is a groove provided on the underside of the casing 1,where the spring 2 extends between the two feet 14. The forward bent-offend 12 of the spring 2 snaps into a recess 20, which is provided on theside of the casing 1 facing away from the valve 3, and whichaccommodates the forward end 12 of the spring 2 with little play so thatthe casing 1 is prevented from getting displaced laterally. The forwardend 12 of the spring 2 is further provided with a hole 18, with a flowchannel, which extends through the casing 1 from the recess 1 to therecess 20, ending behind that hole. There can further be seen a fittingpiece 21, a sealing ring 22 and an internally threaded bush 23 intendedfor mounting the valve 3 on a rim, as well as a screw cap 24 intended toclose the outer end of the valve 3.

[0048] While the embodiments illustrated in FIGS. 1 to 18 are especiallywell suited for deep-well rims, the fourth embodiment illustrated inFIGS. 19 to 21 is especially well suited for flat-base rims. In thiscase, the holder is not constituted by a valve, but rather by a separatesheet-metal part 25 having one portion 28, which is in contact with thebase 26 of the rim 27, and one portion 29, arranged at an angle to, orbent off from the before-mentioned portion, which projects obliquelyfrom the base 26 and comprises a convex shaped projection 30 intended toengage a corresponding concave shaped recess 11 in the casing 1. Theconvex projection 30 and the concave recess 11 preferably exhibitcalotte-shaped surfaces. The projection 30 has a similar design as thevalve base in the preceding examples so that a spring 2 can be held onit, which spring might be configured like the spring in the firstexample, or else like the spring in the second or in the third example.

[0049] In order to mount the holder 25 on the rim 27, the portion 28 ofthe holder 25 is configured as a double loop through which a tighteningstrap 31 can be passed. The tightening strap 31 is then wrapped aboutthe well 26 of the rim and is tightly tensioned, whereby the portion 28is firmly pulled against the rim well 26.

1. An arrangement of a device for measuring the tyre pressure in apneumatic tyre, which device is enclosed in a casing which is locatedinside the pneumatic tyre when the pneumatic tyre has been mounted on awheel, of a spring acting resiliently upon the casing, and of a holderfor the spring, the holder to be fixed on the wheel, the arrangementbeing characterized in that the spring and the casing are so designedand adapted one to the other that the casing finds support on the holderand is clamped for this purpose between the spring and the holder. 2.The arrangement as defined in claim 1, characterized in that the wheelhas a rim with a well and that the spring is so designed and arranged asto push or pull the casing additionally against the rim well.
 3. Thearrangement as defined in claim 1, characterized in that the casing isheld positively as well as under the spring action between the holderand the spring.
 4. The arrangement as defined in claim 1, characterizedin that the casing is provided with a recess for receiving a portion ofthe holder.
 5. The arrangement as defined in claim 1, characterized inthat the holder has a convex end portion.
 6. The arrangement as definedin claim 4, characterized in that the casing is provided with a concaverecess matching the convex end portion of the holder.
 7. The arrangementas defined in claim 1, characterized in that the spring is a leafspring.
 8. The arrangement as defined in claim 1, characterized in thatan annular groove is provided on the holder and the spring is providedwith a fork which can be inserted into said groove.
 9. The arrangementas defined in claims 1, characterized in that a screw is screwed intothat end of the holder on which the casing is supported, that one end ofthe spring is provided with a fork or with a hole, and that said end ofthe spring is clamped between the head of the screw and the end of theholder.
 10. The arrangement as defined in claim 1, characterized in thatthe spring comprises a stirrup which is received by the casing inreceiving means centrally arranged in the casing.
 11. The arrangement asdefined in claim 10, characterized in that the casing ismirror-symmetrical relative to the central receiving means.
 12. Thearrangement as defined in claims 1, characterized in that the springcomprises two mutually parallel stirrups connected by a commonconnecting element for mounting at the holder, and that the casing isprovided with two parallel receiving means for receiving the twostirrups.
 13. The arrangement as defined in claim 12, characterized inthat the receiving means are arranged in symmetry relative to the centreplane of the casing which centre plane contains a longitudinal axis ofthe holder.
 14. The arrangement as defined in claim 1, characterized inthat the underside of the casing is provided with two feet, whichproject from the underside and which are located on different sides ofthe centre plane of the casing, which centre plane contains alongitudinal axis of the holder.
 15. The arrangement as defined in claim1, characterized in that the holder is constituted by a valve with avalve base which is located inside the pneumatic tyre when the valve hasbeen mounted on a wheel.
 16. The arrangement as defined in claim 1,characterized in that the casing is traversed by a flow channel for air,with the valve opening into that channel.
 17. The arrangement as definedin claim 1, characterized in that the wheel has a rim with a well andthat the holder is fixed on the rim by means of a tightening strap whichembraces the rim well.
 18. The arrangement as defined in claim 17,characterized in that the holder has a first portion in contact with therim well and a second portion projecting from the rim well, the casingbeing clamped against said second portion.
 19. The arrangement asdefined in claim 17, characterized in that a loop is formed on theholder through which the tightening strap is passed.
 20. A wheel formotor vehicles with pneumatic tyres comprising a rim, a well formed inthe rim, the base of which is delimited by a sidewall extending at anangle relative to the axis of rotation of the rim (27), a device formeasuring the tyre pressure in the pneumatic tyre, which device islocated in a casing, a spring, and a holder for the spring, which holderis to be mounted on the wheel, the spring acting upon the casing so thatthe casing finds support on the base of the rim well, characterized inthat the spring and the casing are so designed and adapted one to theother that the casing finds support on the holder and is clamped forthis purpose between the spring and the holder.
 21. (Cancelled)
 22. Thewheel as defined in claim 20, characterized in that the casing issupported by the holder and by the base of the rim well, only.
 23. Thewheel as defined in claim 22, characterized in that the casing isprovided with two feet which find support on the base of the rim well.24. The arrangement as defined in claim 5 in which the end portion ofthe holder is in the form of a calotte.
 25. The arrangement as definedin claim 10 in which the receiving means is a shallow groove.
 26. Thearrangement as defined in claim 12 in which the receiving means are twoshallow grooves.